Plumb-bob.



PATENTED APR. 25, 1905.

INVENTOR o an 4. Q I? 0 J a 9 \\v. I: WK .ix I V W.

M. D. CONVERSE.

PLUMB BOB.

APPLICATION FILED DEC. a, 1903.

UNiTEp STATES Patented April 25, 1905.

MASCHIL D. CONVERSE, OF NEWARK, NEW JERSEY.

PLUlVlB-BOB.

EECIFICATION forming part of Letters Patent No. 787,896, dated April 25,1905.

Application filed December 9, 1903. Serial No. 184,450.

.To (1H "'71 (1711/ if m r/y concern:

Be it known that l, Hasoiin. l). Coxvnnsn, a citizen of the UnitedStates, residing at New ark, in the county of Essex and State of NewJersey,have invented new and useful Improvements in Plumb-Bobs, of whichthe following is a specification.

My invention relates to plumb-bobs, and particularly to those types thathave been made with an interior chamber filled with lead or other metalof great specific gravity.

My invention is comprised in certain novel forms of parts and details ofconstruction and in their combination; and the objects of my inventionare to overcome certain difficulties heretofore experienced in themanufacture of plumb-bobs, to cheapen the cost of manufacture, to insuregreater perfection in such implements, and to render them more efficientand less liable to injury or derangement in use, all which will behereinafter fully described and distinctly claimed.

In the drawings, Figure 1 is a vertical sectional view of my improvedplumb-bob assembled; Fig. 2, a similar section of the shell or case onlyin one form before the same has been tilledwith lead. Fig. 3 is thescrew-cap, and Fig. & the stem, carrying a point at one end and ascrew-threaded reduced portion at the opposite end upon which the cap,Fig. 3, is secured. Fig. 5 is a plan view. Fig. 6 is a section similarto Fig. 1, but of a modified form of shell or case filled with lead,with the stem and cap removed.

Like letters indicate corresponding parts throughout the severalfigures.

A is the shell or case, which 1 make of a uniform gage of metal, usuallysheet-brass, by spinning or stamping, and which may be made in two ormore parts and joined by a seam forming a bead orotherwise, as at u,(see Figs. 1, and 5,) or may be made seamless, as in Fig. 6.

L is the filling for giving it weight, usually of lead,-but may be ofother heavy metal.

S is a stem, preferably of steel, finished with a point p at itslowerend and made with a shoulder s. removed from and preferably midway ofits ends, so as to be located within the filling L of the body portionwith the re- I duced part 1- at the upper end, the latter beingscrew-threaded at f, upon which a cap C, correspondingly threaded, isscrewed. This cap C is provided with a hole it centrally through its topby which to fasten a cord for suspending the plumb-bob, and the hole ftherein is of sufficient depth to freely accommodate a knot at the endof said cord to prevent its coming out. This cap I prefer to make withan annular flangef to fit over an annular flangef' around the centralopening at the upper end of the shell G.

In Figs. 2 and 6 the lower end of the shell at f is straight orterminated like a tube, while in Fig. l at f this straight or tubulartermination has been spun or crimped into a neck 11 in the stem S,situated just at the base of its conical point p.

Heretofore in making plumb-bobs with hollow interiors to be filled withlead or other weighty metal the shells have been molded or cast, usuallyof brass, and the chambered interior formed by means of a sand core. Inthis process the cores usually sag or wash, with the result that theplumb-bob shells have unequal thickness of wall, one side being thin andthe opposite thick, and but rarely, if ever, can be castwith a perfectlyuniform thickness of shell throughout, so that when shells thusdefective are filled with lead a preponderating quantity of the latterruns to the larger side of the chamber, which of course is on the sidewhere the shell is thinnest,and hence the center of gravity is not, asit should be, through the vertical longittulinal axis,andconsequentlythe pointof the plumb-bob will when suspended for use gyrateand fail to come to rest promptly. Furthermore, shells so made aretroublesome and expensive to turn up, machine, and finish. Thesedifliculties my prescntinvention wholly overcome, as will be seen,because the shell being of uniform thickness in any given zone andequidistant from the longitudinal axis causes equal distribution of leadwhen filling, and having already a smooth exterior surface my improvedplumb-bobs do not require to be turned at all, but may be polished andfinished with facility.

I prefer to construct my plumb-bob with the annular bead u at thebroadest diameter (see Fig. 1) and to make the conical point so that atp the base of its cone will extend beyond the exterior surface of theshell in order that when the plumb-bob is placed upon its side on alevel surface (see line y 3/ in Figs. 1 and 6) it may contact at twopoints only, and thus be afforded some protection against marring orbruising of the body of the same.

In filling the shells of my improved plumbbobs I prefer to arrange themupon false or temporary stems having the same diametral dimensions asthe permanent ones and also formed with a like suitably-located shoulders, then withdraw the former to insert the latter. It will be seen andunderstood that in so doing the shoulder s of the stem abuts theshoulder 8 formed in the lead filling, and that the latter is arrangedto be at about where the greatest volume of filling and consequentgreatest resistance against displacement occurs, so that when the capCis screwed down the whole is securely assembled, and then bycrowdingthe shell at f into the neck, as at all parts are further madefirm.

Other forms of stem than that I have shown may be used in connectionwith my improved shell without departing from the spirit of this part ofmy invention, and other forms of shell likewise may be used inconnection with my improved plumb-bob stem without departing from thespirit of this part of my invention.

Having described my invention, what I claim as new, and desire to secureby Letters Patent, is*

1. A plumb-bob comprising a shell of uniform thickness of wall in anygiven Zone,open at top and bottom, a filling pierced vertically by astem, shouldered midway of its ends, and having a conical point with aneck at the base of the cone, and provided with screwthreads at theopposite upper reduced end, in combination with acorresponding]y-screwthreaded cap.

2. A plumb-bob comprising a shell of uniform thickness of wall in anygiven zone,open at top and bottom, a filling pierced vertically by astem, shouldered midway of its ends, having a conical point and providedwith screw-threads at the opposite upper reduced end, in combinationwith a correspondinglyscrew-threaded cap.

3. A plumb-bob comprising a shell of uniform thickness of wall in anygiven zone, having a bead at its greatest diameter, and open at top andbottom, a filling pierced vertically by a hole having a reduced diameteralong its upper part, a stem conformed to the shape of this hole havinga conical point with a neck at the base thereof and screw-threads at theopposite reduced end, in combination with acorrespondingly-screw-threaded cap.

i. A plumb-bob comprising a shell of uniform thickness of wall in anygiven zone, having a bead at its greatest diameter, open at top andbottom, a filling pierced vertically by a hole having a reduced diameteralong its upper part, a stem conformed to the shape of this hole havinga conical point, and screwthreads at the opposite reduced end, incombination with a correspondingly-screw-threaded cap.

5. Aplumb-bob comprising a shell of uniform thickness of wall in anygiven zone, having a head at its greatest diameter, open at top andbottom, a filling pierced vertically by a hole having a reduced diameteralong its upper part, a stem conformed to the shape of this hole havinga conical point with a neck at the base thereof said base extendedbeyond the exterior surface of the shell, and screwthreads at theopposite reduced end, in combination with acorrespondingly-screw-threaded cap.

6. A plumb-bob comprising a shell of uniform thickness of wall in anygiven zone, having a bead at its greatest diameter, open at top andbottom, a filling pierced vertically by a hole having a reduced diameteralong its upper part, a stem conformed to the shape of this hole havinga conical point with the base thereof extended beyond the exteriorsurface of the shell, and screw-threads at the opposite reduced end, incombination with a correspondingly-screw-threaded cap. 7. A plumb-bobcomprising a shell of uniform thickness of wall in any given Zone, openat top and bottom, a filling pierced vertically by a hole having areduced diameter along its upper part, a stem conformed to the shape ofthis hole having a conical point with a neck at the base thereof andsaid base extended beyond the exterior surface of the shell, andscrew-threads at the opposite reduced end, in combination with acorrespondingly-screwthreaded cap.

8. In a plumb-bob a filled shell, having an annularly-fianged opening atits top, mounted upon a shouldered conical-pointed stem, with screwthreaded upper end, in combination with a flanged screw-cap.

9. In a plumb-bob a shell terminated by a tubular opening at its lowerend, in combination with a conical-pointed stem entered therethroughprovided with a neck into which the end of said tubular termination iscompressed.

10. A plumb-bob comprising a body portion, ahead at the greatestdiameter of said body portion, mounted upon a shouldered conical-pointedstem, having screw-threads at its upper reduced end, and having the baseof said cone extended annularly beyond the exterior surface of said bodyportion, in combination with a screw-cap.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

MASCHIL D. CONVERSE.

Witnesses:

W. E. 'WRIGHT, R. W. RowE.

